In recent years, infrared light imaging devices have been widely used in the fields of medical image diagnosis devices, night surveillance camera, night vision system for driving, biometric identification, machine vision, testing of food quality, detecting surface of industrial products and etc, and can further be used in more fields benefited from the development of mobile terminal like cell phones. Though a human vision is sensitive only to visible light from 400 nm to 760 nm, by adopting materials sensitive to invisible light wavebands, from X ray to far-infrared light, invisible image can be converted into electronic image and displayed in the form of visible light image, and thus can be viewed by naked eyes indirectly. In order to establish a comprehensive understanding for an object, human brain or artificial intelligence has to associate the image data sets in multiple wavebands pixel by pixel. For this reason, acquiring multispectral image data in the same viewing angle and in the same time becomes absolutely necessary.
For this purpose, a multispectral imaging system with dual cameras which capture visible light and infrared light respectively has been developed. The dual-camera system, however results in large body and weight, and therefore high cost. Two optical axes in the dual-camera system inevitably add a complicated image data calibration process. To avoid these problems, an imaging device sensitive to both visible light and infrared light also has been developed, such as a CCD or CMOS imaging device formed on a silicon chip, to collect and process images of visible light and infrared light respectively in different time slots. However, this kind of imaging device, no matter adopting a mechanical chopper or an electronic shutter, comes with not only a complex structure, but also position errors for moving objects.